Systems and methods for neutralizing explosive devices

ABSTRACT

An apparatus for neutralizing an explosive comprises a housing including at least one relief groove along an outer portion of the housing, and an inner chamber. The inner chamber includes a first hollow section and a second hollow section. The cross-sectional area of the second hollow section is smaller than the cross-sectional area of the first hollow section. A forward section of the housing is adapted to receive a first nose member and a rear section of the housing is adapted to receive a removable fin set.

STATEMENT OF GOVERNMENT INTEREST

This invention was made with government support under 2007-DE-BX-D002 awarded by National institute of Justice. The government has certain rights in the invention.

BACKGROUND

Vehicle-borne improvised explosive devices (VBIEDs) have been used by terrorists with increasing effect in recent years. In the United States, neutralization of explosive devices is the role of bomb-disposal squads, which form part of the domestic first-responder network. However, there is at present no protocol for responding to VBIEDs. The percussion-actuated nonelectric (PAN) disruptor technologies currently used by domestic bomb squads are not suited for a vehicle-borne device in which the detonation train is not readily accessible. Solutions developed in Europe involve large amounts of explosives to drive water disruptors, which cause collateral damage that would be unacceptable in many areas in the United States.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the present invention may be better understood, and their numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.

FIG. 1A shows a perspective view of an embodiment of an apparatus that can be used as a projectile to neutralize an explosive device.

FIG. 1B shows a cross-sectional side view of the apparatus of FIG. 1A.

FIG. 1C shows a perspective view of the apparatus of FIG. 1A with fins deployed.

FIG. 2A is a perspective view of an embodiment of a first nose section that can be used with the apparatus of FIG. 1A.

FIG. 2B is a cross-sectional diagram of the nose section of FIG. 2A.

FIG. 2C is a perspective view of an embodiment of a first nose section that can be used with the apparatus of FIG. 1A.

FIG. 2D is a cross-sectional diagram of the nose section of FIG. 2C.

FIG. 3A is a perspective of an embodiment of a fin set that can be used with the apparatus of FIG. 1A.

FIG. 3B is a side-cross-sectional diagram of the fin set of FIG. 3A.

FIG. 4A is a side view of an explosive device being penetrated by an embodiment of the apparatus of FIG. 1A.

FIG. 4B is a side view of the explosive device of FIG. 5 after being neutralized by the apparatus of FIG. 1A.

DETAILED DESCRIPTION

Embodiments of systems and methods are disclosed that can neutralize an explosive substance in an Improvised Explosive Device (IED) using a projectile containing relatively small amounts of a reactive material. The impact of the projectile on the IED container initiates the reactive material, which causes a controlled reaction, e.g., a deflagration as opposed to a detonation, of the explosive. This reaction creates sufficient pressure to rupture plastic or steel containers producing a neutralization or render-safe outcome. Use of the projectile to neutralize an IED from a safe standoff distance improves bomb squad operational tactics and provides ability to rapidly neutralize explosive devices. Additionally, the limited deflagration leaves more of the IED intact and aids post mortem forensic analysis.

Referring to FIGS. 1A-1C, an embodiment of an apparatus that can be used as a projectile 100 to neutralize an explosive device is shown including a housing 102 having at least one relief groove 104 along an outer portion of the housing 102. Housing 102 can be cylindrical or other shape suitable for being launched from the muzzle of a launcher or gun. For example, projectile 100 can be fired from a 12 gauge PAN disruptor manufactured by Ideal Products, Inc., or other suitable gun or launcher. Projectile 100 is designed to remain stable during flight so that the projectile 100 hits the target nose first.

Groove(s) 104 define the location(s) where the housing 102 will rupture upon impact and penetration into an explosive device due to stress concentrations on the thinnest parts of the wall of the housing 102. The reactive material will then leak out through the ruptured areas of the housing 102 into the explosive material. Groove(s) 104 can be oriented in any suitable direction along housing 102, such as along the longitudinal axis, around the circumference, and/or diagonally across the housing 102. For example, in some embodiments, housing 102 can be 3.5 inches long with an outer diameter of 0.725 inches. Six grooves 104 are positioned along the longitudinal axis of housing 102 at equal intervals around the outer diameter of housing 102. The grooves 104 can be approximately 2.5 inches long with a 0.625 inch radius arcuate cross-section approximately 0.0175 inches deep, and 0.18 inches wide. The mass of projectile 100 can be 65 grams, or other suitable mass depending on the thickness and rigidity of the outer shell of the explosive device. The shape of the explosive device, for example, the diameter of the container, is another factor to consider when selecting a particular size and mass for projectile 100. For example, containers with flatter surfaces may be easier to penetrate than containers with more rounded side walls. Other suitable dimensions, mass, and shapes for the projectile 100 and the groove(s) 104 can be used.

Projectile 100 further includes an inner chamber comprising a first hollow section 106 and a second hollow section 108. The cross-sectional area of the second hollow section 108 is typically smaller than the cross-sectional area of the first hollow section 106. In one embodiment, hollow sections 106, 108 have a cargo capacity of 8 cubic centimeters, which will hold approximately 16 grams of reactive material. Hollow sections 106, 108 can be configured to hold other suitable volumes, however.

A chamfered shoulder portion 110 can be included between the first and second hollow sections 106, 108 to gradually transition from the cross-sectional area of hollow section 106 to the cross-sectional area of hollow section 108. A rounded portion 112 can be included at the end of the second hollow section 108. The shoulder portion 110 and rounded end 112 reduce the pressure forces imposed by rapidly accelerating reactive material on the inner portion of the housing 102 when projectile 100 is fired or launched.

The housing 102 can further include forward section 114 adapted to receive a first nose member 116 and a rear section 118 adapted to receive a fin set 120. More than one nose member can be used in situations where projectile 100 is required to penetrate more than one layer of covering around the explosive substance. For example, the explosive device may be located in a truck or automobile, and the projectile 100 is required to penetrate a panel of the vehicle and then a sidewall of the explosive device. Accordingly, an expendable second nose member 122 can be attached to the first nose member 116 to absorb the shock of the impact with the first obstacle and help prevent the housing 102 from rupturing. The first nose member 116 is then available to penetrate the side wall of the explosive device.

FIGS. 2A-2D show embodiments of first and second nose sections 116, 122. The external forward section 114 of the housing 102 (FIG. 1A) can be threaded to mate with a threaded base portion 202 of the first nose member 116. Similarly, an external forward section 204 of the first nose member 116 can be threaded to mate with a threaded base portion 206 of the second nose member 122. Other suitable means for attaching nose sections 116, 122 to housing 102 can be used.

Additionally, the external face of nose sections 116, 122 can be blunt, slightly rounded, or pointed. The threaded portion 204 of the first nose member 116 can be frangible so that the second nose portion 122 and the threaded portion 204 break off from the first nose portion 116 upon impact with the first obstacle.

Referring to FIGS. 3A and 3B, perspective and side cross-sectional views of an embodiment of the fin set 120 (FIGS. 1A-1C). In the embodiment shown, the fin set 120 is formed by a cylinder 302 that is closed on one end 303 and includes a hollow inner section with tapered sidewalls 304 that increase the hollow area toward an open end of the cylinder 302. The tapered sidewalls 304 are shown including a plurality of fin portions 306. A threaded base portion 308 on the external portion of the closed end of the cylinder mates with the threaded rear section 118 of the housing 102 (FIG. 1B). Other suitable means for attaching fin set 120 to housing 102 can be used.

The fin set 120 further includes a plurality of longitudinal cuts 310 spaced around the circumference of the cylinder 302. The longitudinal cuts 310 extend through the sidewalls 304 of the cylinder 302 to form the individual fin portions 306. Lateral notches 312 can be formed or cut through the sidewalls 304 of the cylinder 302 at the base of the longitudinal cuts, adjacent the closed end 303 of the cylinder 302.

The fin portions 306 are configured to bend into a deployed position by blast pressure behind the fin set as the projectile 100 exits a muzzle of a gun or launcher. FIG. 1C shows a perspective view of an embodiment of the projectile 100 with the fin portions 306 deployed. Note that other means for deploying the fins after launch can be used, such as spring loaded fins, aerodynamic deployment, etc.

Referring to FIGS. 1A-1C and 4A-4B, FIG. 4A is a side view of an explosive device being penetrated by an embodiment of the projectile 100. FIG. 4B is a side view of the explosive device of FIG. 4A after being neutralized by the projectile 100. A reactive material stored in an inner chamber of housing 102 is initiated by the ballistic impact with the container 400. The reactive material causes a reaction with a limited amount of the explosive substance that builds overpressure in the target container. The target container ruptures due to the pressure, thereby neutralizing the explosive device without detonating the explosive substance. At least some of the explosive material may empty out of container 400. The explosive material can be wetted down with water from a fire hose to further neutralize the explosive material.

In some embodiments, projectile 100 is configured to survive launch breech pressure of approximately 45,000 psi, acceleration of approximately 10⁵ g, and cargo pressure of 15,000 psi; (2) deploy fins symmetrically and survive muzzle blast pressure of approximately 4300 psi to 6000 psi; (3) transition to stable flight in less than 10 meters; (4) impact drum at small (˜10°) yaw angle; and (5) impact within a defined velocity range.

The reactive material is configured to initiate from ballistic impact shock and react inside the explosive device. The impact of projectile 100 with the explosive device can create a critical mass (approximately ½ kg to 1 kg) of ANFO Crush Zone (CZ) to react with the reactive material. The velocity of the projectile 100 should be high enough to penetrate the explosive device without detonating the explosive device. If combustion is too slow, the reactive material may not deflagrate a sufficient amount of the explosive material to rupture the container.

Examples of common explosive substances used in IEDs for which this technology is suitable include but are not limited to Ammonium Nitrate Fuel Oil (ANFO), powdered ammonium nitrate and aluminum powder (AN/AI) and urea nitrate. The reactive material is chosen to cause a vented deflagration when the reactive material is released into the explosive substance. Examples of suitable reactive materials include: conventional thermites, e.g micrometer particle size aluminum and copper oxide; conventional thermites with gas generation additives, e.g. sodium azide; and aluminum in both nanometer and micrometer particle size with liquid oxidizers, e.g. perfluoropolyether.

Experimental testing demonstrated that the reactive material causes a controlled reaction of a sufficient mass of ANFO and AN/AI so that the resulting pressurization from the controlled reaction of the explosive causes the container to rupture without transitioning to a detonation. Experimental trials demonstrated that both plastic and steel containers containing between 40 lb and 110 lb of ANFO could be successfully rendered safe using 16 grams of reactive material. Other combinations of amounts of explosive material and reactive material can be used.

In another series of experiments conducted with steel pipe bombs, it was established that 6 grams of reactive material consistently gave rise to a propagating reaction in the ANFO in which a quarter to half of the ANFO was consumed in a deflagration. It was also found that only a few hundred grams of burning ANFO produced sufficient gas to rupture a container without fragmentation. Tests conducted on a six-inch pipe bomb containing 660 g (1.5 lb) of ANFO demonstrated a repeatable deflagration with fracture of the pipe bomb using 6 grams of reactive material.

Consequences of the rupture are that the ANFO bulk is no longer detonatable. Moreover, the ANFO is exposed and can be further neutralized by spraying the explosive material with water or other anti-inflammatory substance.

Thus, a method for neutralizing explosive material within a container using projectile 100 can include filling a projectile with a reactive material. The reactive material is formulated to react with a portion of the explosive material to build internal pressure and rupture the container without detonating the explosive material. One or more nose portions 116, 122 are selected for the projectile based on one or more factors such as but not limited to predicted impact velocity of the projectile with the container, the material strength and shape of the container, distance to the container, the mass of the projectile, and the type of explosive material. A fin set 120 is also selected for the projectile 100 based on blast pressure behind the projectile when the projectile is fired from a gun; length, diameter, and mass of the housing, mass; and mass of the reactive material.

If the explosive device is hidden in a vehicle, e.g a panel truck or other thin skin structure, the explosive device may be exposed using a relatively low-speed projectile containing a thermobaric (TBX)—type explosive fired into the vehicle. The pressure output of the TBX could be controlled by the initiation scheme. Reaction of the low explosive within the vehicle would remove the sides of the cargo compartment, revealing the explosive device.

Alternatively, a back-scatter X-ray system can be used to locate the explosive device inside a vehicle or other structure. One or more projectiles 100 with two nose portions 116, 122 could be fired through the side of the vehicle/structure into the explosive device. The dual nose configuration of the projectile 100 would allow penetrate through the wall of the vehicle but not release the reactive material until the projectile 100 penetrated the container of the explosive device.

If a firing circuit on the explosive device is visible, the circuit could be disabled with conventional PAN disruptor projectiles. But if the circuit is not visible, the explosive device would be rendered safe by shooting the projectile 100 through the container. The outcome of the impact will either be massive spillage of explosive material from the container, or at the very least a large hole into the container. In the latter case, a high-pressure water stream would be directed into the hole, which will dissolve the exposed contents.

While the present disclosure describes various embodiments, these embodiments are to be understood as illustrative and do not limit the claim scope. Many variations, modifications, additions and improvements of the described embodiments are possible. For example, those having ordinary skill in the art will readily implement the processes necessary to provide the structures and methods disclosed herein. Variations and modifications of the embodiments disclosed herein may also be made while remaining within the scope of the following claims. The functionality and combinations of functionality of the individual modules can be any appropriate functionality. Additionally, limitations set forth in publications incorporated by reference herein are not intended to limit the scope of the claims. In the claims, unless otherwise indicated the article “a” is to refer to “one or more than one”. 

1. An apparatus for neutralizing an explosive comprising: a housing including: at least one relief groove along an outer portion of the housing; an inner chamber, the inner chamber includes a first hollow section, a second hollow section, the cross-sectional area of the second hollow section is smaller than the cross-sectional area of the first hollow section; a forward section adapted to receive a first nose member; and a rear section adapted to receive a removable fin set.
 2. The apparatus of claim 1, further comprising: a shoulder portion between the first and second hollow sections.
 3. The apparatus of claim 1, further comprising: the second hollow section includes a rounded end.
 4. The apparatus of claim 1, further comprising: a fin set attached to the housing.
 5. The apparatus of claim 1, further comprising: the first nose member attached to the housing.
 6. The apparatus of claim 4, further comprising: the fin set includes a plurality of fin portions that are bent into a deployed position by blast pressure behind the fin set as the apparatus exits a muzzle of a gun.
 7. The apparatus of claim 1, further comprising: the external rear section of the housing is threaded; and the fin set includes a threaded base portion that mates with the threaded rear section of the housing.
 8. The apparatus of claim 1, the fin set further comprising: a hollow cylinder including a plurality of longitudinal cuts spaced around the circumference of the cylinder and lateral notches through the cylinder at the base of the longitudinal cuts.
 9. The apparatus of claim 1, further comprising: the external forward section of the housing is threaded; and the first nose member includes a threaded base portion that mates with the threaded forward section of the housing.
 10. The apparatus of claim 1, further comprising: a second nose member attached to the first nose member.
 11. The apparatus of claim 1, further comprising: a reactive material in the inner chamber, the reactive material is formulated to neutralize the explosive; and the relief grooves are configured to provide an opening for the reactive material to disperse from the housing upon impact and penetration into a target containing the explosive.
 12. The apparatus of claim 11, further comprising: the reactive material is one of the group consisting of: APEX and thermite.
 13. A method for neutralizing explosive material within a container comprising: filling a projectile with a reactive material, the reactive material is formulated to react with a portion of the explosive material to build internal pressure and rupture the container without detonating the explosive material; selecting a nose portion for the projectile, the nose portion is selected based on predicted impact velocity of the projectile with the container and the material of the container; and selecting a fin set for the projectile based on blast pressure behind the projectile when the projectile is fired from a gun.
 14. The method of claim 13 further comprising: attaching a second nose member to the first nose member.
 15. The method of claim 13, further comprising: selecting an amount of the reactive material. 